Interaction of Some Amino Acids with Sodium Dodecyl Sulphate in Aqueous Solution at Different Temperatures
Anwar Ali, Firdoos Ahmad Itoo, and Nizamul Haque Ansari
Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi – 110 025, India Reprint requests to A. A.; E-mail: anwarali.chem@gmail.com
Z. Naturforsch.66a,345 – 352 (2011); received August 9, 2010
The densityρ, and viscosityη of 0.00, 0.05, 0.10, 0.15, and 0.20 mol kg−1 glycine (Gly), dl- alanine (Ala), dl-serine (Ser), and dl-valine (Val) have been measured in 0.002 mol kg−1aqueous sodium dodecyl sulphate (SDS) at 298.15, 303.15, 308.15, and 313.15 K. These data have been used to calculate the apparent molar volumeφv, infinite dilution apparent molar volumeφv◦, and the standard partial molar volumes of transferφv◦
(tr), of the amino acids from water to the aqueous SDS solutions. Falkenhagen coefficientA, Jones-Dole coefficientB, free energies of activation per mole of solvent (aqueous SDS)∆µ1◦∗, and per mole solute (amino acids)∆µ2◦∗, also enthalpy∆H∗and entropy∆S∗of activation of viscous flow were evaluated using viscosity data. The molar refraction RDwas calculated by using experimental values of the refractive indexnDof the systems. The results have been interpreted in terms of ion-ion, ion-polar and hydrophobic-hydrophobic group interactions.
The volume of the transfer data suggest that ion-ion intertactions are predominant.
Key words:Density; Viscosity; Refractive Index; Amino Acids.
